This invention relates to sprayable agricultural compositions, and to a method of reducing or preventing precipitation of calcium polysulfide from an aqueous solution in which it is present in a low concentration.
It is known to apply calcium polysulfide solutions to soil used for agricultural purposes. Calcium polysulfide supplies calcium and colloidal sulfur to the soil, both being crucial plant growing nutrients. In alkaline soil it lowers the pH. It acts as a fungicide, insecticide and a miticide for fruits, nuts, ornamentals, roses, etc.
Calcium polysulfide is applied by adding it to irrigation water or shank injection. However, it cannot be applied through drip or sprinkler irrigation systems because the calcium precipitates and plugs the system.
Sodium methyldithiocarbamate is a common fumigant system used for suppression of nematodes, fungi, bacteria, weeds, weed seeds and volunteer seeds. This material is supplied in aqueous solution, and is applied to agricultural soil after harvest and up to 14 to 21 days before a new crop is planted. It is applied to the field through drip or sprinkler irrigation. However, it cannot be applied together with calcium polysulfide because it would cause the sodium methyldithiocarbamate to precipitate.